Why Gerardi is a dwarf mulberry

You’ve created some strange-looking beasts… It will be interesting if they retain their leaf form as they mature.

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I think it would actually be an almost impossible task trying to classify mulberry varieties (not wild species) through genetic analysis because of the complexi hybridization. All mulberries within the “alba” group (this means nearly all mulberry varieties known today) hybridize readily among the species and subspecies and more recently also with Morus rubra. Considering that this hybridization has been going on for centuries I presume that the genetic composition of these hybrid varieties has become so complex that it is impossible to classify them into one or other species or subspecies.
About using the dwarf hybrids as dwarfing rootstock: this will only be helpfull if the rootstock actually has a weaker rootsystem in comparison to other mulberries. Gerardi Dwarf has a normal vigorous rootstock and is dwarfish because of the very short internodal distance. It is a genetic dwarf with normal rootsystem and as such it has no dwarfing influence on the variety grafted onto it. compare with apple rootstock: M9 and M27 are very weak rooting apple rootstock and will therefore induce weak growth on the variety grafted onto it and because of weak root system these will also need life long staking. To my knowledge such a rootstock does not yet exist among mulberries…

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In retrospect, I now believe @Richard is correct (That ‘Gerardi’ isn’t a Morus nigra hybrid). A paper describing Morus nigra hybrids seems to imply that Morus nigra hybrids all have 168 chromosomes (154chromosomes from nigra plus 14 from a 28-chromosome parent). Also, @Mikatani confirmed that all the nigra crosses he has produced were 168 chromosome hybrids. The microscopic image I presented above shows nuclei with a diameter consistent with most non-nigra nuclei (like Morus rubra, alba, macroura). If is were truly a Morus nigra cross, having 168 chromosomes, it would be much, much larger.
It was, though, a story worth consideration, but from reading his obituary, it would appear that Louis Edward Gerardi spent his entire life living in Illinois. The story claims that ‘Gerardi Dwarf’ was obtained by crossing a Morus nigra with ‘Himalayan Long’, both of which would only survive in Illinois in greenhouse conditions. Not impossible, but not practical for someone whose main interest was in growing dahlia.
Morus nigra hybrid.pdf (3.4 MB)

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I’ve got a Gerardi I purchased from Edible Landscaping this year and since it was so small (4 inches and quarter pencil-thickness) I planted it in a 2 gal pot for this season.

In one season this plant has grown from 4 inches to over 6 feet and the thickness is just about pencil thickness.

Is this wonderful growth indicative that what I received is not likely a Gerardi?

Scott

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If you could provide a photo or two it would be very helpful. Six feet in one season is very suspicious. ‘Gerardi’ has a very short internode distance that is about half the distance of a regular mulberry, and for that reason, it was incorrectly assumed that it was a Morus nigra hybrid (Morus nigra, true Black Mulberry, also has a very short internode distance).

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I grafted gerardi dwarf scions onto a 4 inch thick white mulberry stump this spring. Several of the shoots are over 6 ft tall now.

Good shot of the leaves and nodes above.

The nodes are tight… average 1 to 1.5 inches between nodes.

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I looked and all the nodes are just about 1.5 inches…

The leaves look similar (but mulberry leaves do that).

I failed to control an Illinois Everbearing. This one will replace a World’s Best most likely. Perhaps it will slow down once put into the ground next spring… At least I hope so.

Scott

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Can you send gerardi cutting to india

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The only reports I have seen describing the chromosome number in M. macroura, say that it is tetraploid, but there are very few examples. I noticed that @Richard has listed it as such several times. While it is very possible that M. macroura could have different ploidy races, it is also possible that these hybrids between M. macroura and M. nigra actually have 182 chromosomes and not 168 (which would be expected from a cross with diploids). I assume that flow cytometry was used to estimate ploidy in these hybrids? I really doubt that flow can distinguish between 168 and 182. @Mikatani Has your M. macroura that was crossed with M. nigra been checked for ploidy? I’m really curious if M. macroura cultivars like ‘Pakistan’ are really tets.

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Just checked the top 12 inches of one of my gerardi shoots… and found 16 buds. There are some on the back side you cant see in the pic.

Checked my new silk hope… top 12 inches has 4 buds.

Gerardi is packing a lot in a small space.

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From my post earlier (1st in this thread):

I measured how many fruit were within a length of 3 cell phones (later found to be 15"):

Gerardi- 88-102 fruit, 3-6 fruit per cluster
IE- 26-27, 4-5 per node
Kokuso- 25-28, mostly 4/node
Oscar- 16-18, mostly 3/node

So translating that to buds per foot:
Gerardi- about 18 buds per foot
IE- 4-5 buds
Kokuso- 5-6 buds
Oscar- 4-5 buds

Which means that my results from 2017 roughly match what you are seeing (4 for Silk Hope and 16 for Gerardi vs 4-6 for non-Gerardi and ~18 for Gerardi for me).

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No, my macroura (“Pakistan”) wasn’t tested for ploidity but I have always asumed it to be tetra…I remember having read an article on the subject but can’t remember when or where…

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I have the same question. I also got a couple tiny (2 inch pot) Gerardi’s from E.L. two years ago, and they’ve both put on quite a bit of growth (they are 8 or 9ft, and that’s only because I’ve pruned them to stay that short).

I’ve also had good success rooting stem cuttings from them (~80-90%). But, from what I’ve read, Gerardi is very difficult to root.

I’ve only had a small harvest from them so far. But the growth form and fruit (taste, appearance, and timing) make me wonder if it’s just a ‘Dwarf Everbearing’ mulberry. I ordered some Gerardi scions from Fruitwood Nursery this winter and grafted them onto my E.L. ‘Gerardi’ to see if i notice any differences.

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I have a Gerardi grafted to a IE and in 4 yrs it has grown about 5 ft.

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@alliumnate and @Chills What you describe, the rate of growth and the ability to root cuttings, certainly doesn’t sound like Gerardi. The distance between buds and the thickness of the growth may also be an indicator you can look at. My neighbor has a dwarf everbearing type and the growth is definitely not as chunky as the growth on my Gerardi. His trees are from EL and he has to prune them every year to keep them from pushing over 15 feet.

Also, have you been getting fruit? If you haven’t been getting fruit yet, it definitely isn’t Gerardi. Mine has been fruiting since I got it 6 years ago when it was 18 inches tall. My original tree came from the wonderful Lucille of Whitman Farms.

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@BobVance — ever tried Silk Hope ?

I was wondering where it might land in your ranking…

1.) Oscar
2.) Taiwanese Everbearing
3.) Illinois Everbearing
4a.) Gerardi
4b.) Pakistan
5.) Kokuso
6.) Wellington

==
I have Gerardi and a new Silk Hope…
Should get lots of Gerardi fruit this year… but it may be next year, or later… on Silk hope, it is just a single stem whip now. I have found people growing it, tasting it on youtube that talk like it taste very good.

I may have to add a Oscar some day to see how they compare.

Per Strudledog in North GA - not that far from me…(youtube vid) his Gerardi fruit starts ripening end of April and continues ripening fruit until end of June. (2 months).

Do any of you know the fruiting period for Oscar, Silk Hope ? from when to when ? ripe fruit ?

Wondering if there are any good varieties worth adding simply because they fruit earlier or later than the others I have ? (Gerardi, Silk Hope) Can you extend the ripe mulberry harvest period with a combo of specific varieties ?

I doubt any are going to ripen before end of April… but are there any varieties that ripen mid July or later ?

Thanks
TNHunter

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I’d be very suspicious that it isn’t really a Gerardi. You may want to try measuring between the buds and see how it compares to the values posted by me and TNHunter.

Sounds about right. Just from memory, I think mine was about 6’ tall after maybe 5 years.

I grafted it years ago (just checked- 2016), but don’t remember ever getting fruit. I’m guessing the graft either failed, or got shaded out,

I feel like muberries get a bit too large too quickly for my preference. But Oscar is one that could be worth it. It’s basically a better-than-average blackberry. I did plant one at another rental this winter. I have Oscar grafted low (2-4’) and Gerardi at the top (5-6’), with the idea that I’ll let Oscar send out some long horizontal branches and keep it short by only allowing Gerardi to grow upwards. We’ll see…

I think Oscar covers most of June, but not much before that. Sounds like they ripen over a longer period for Strudledog in GA.

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Based on everything you’re saying, I would definitely suspect a mislabeled tree.You should post some pictures of the wood. The stems and buds of Gerardi are quite distinctive. The leaves are also stiff and bristly compared to others, with a very uniform appearance, non of the assymetry and lobing so common to mulberries. Having grown it and gotten to know it, I could tell it from a picture very easily. Look at the pics posted by TNHunter above- that’s the one. The fruit is identifiable too. I’d describe it as most similar in size and shape to Illinois Everbearing, among the varieties I grow. It’s very precocious and the fruit is quite long and fat, too. I wish they tasted a little better. For me (perhaps it’s soils, climate, who knows) they’re a bit on the flat and watery side. They look big and beautiful, but I think even my Tea’s weeping which has quite run of the mill alba flavor, might a bit richer.
I’ve heard people say that Gerardi is excellent for them, and I don’t doubt it. A lot of anecdotal info would suggest mulberry varieties really vary a lot by where they’re grown.

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I don’t have Silk Hope, but Oscar’s has quite a short window here (Vermont) of about 2 weeks, roughly July 1-July15 most years, I’d say

Oscars has exceptional flavor, IME. The balance of sweet and tart is just right, it reminds me of the perfect lemonade, or even of my experience eating miracle fruit and lemon at the Fruit and Spice Park in Homestead, FL. Afterwards, we made our way over to the mulberries as gorged on Pakistan, Shangri La, who knows what else. So tasty!

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This lady agrees that Oscar is delicious.
Just listen to her as she is eating them… funny.
Makes me want one… but it looks like a giant compared to my gerardi.

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